I really like the ideas of Grand balls. Although its going to be hard for my firstborn daughter to dance (Full-blood Cloudiz --> Fishtail).
On the topic of that, my second born daughter is only 10 at the start of the game, but she is aviable for marriage in a few turns if somebody want to have a wife with dragonfly wings and an affinity for magic .
Although to manage that you got to get to very very good terms with the Kasumor Royal family, which might prove time consuming.